/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.jetbrains.rest.completion;

import com.intellij.codeInsight.completion.*;
import com.intellij.codeInsight.lookup.LookupElementBuilder;
import com.intellij.patterns.PsiElementPattern;
import com.intellij.psi.PsiElement;
import com.intellij.util.ProcessingContext;
import com.jetbrains.rest.RestTokenTypes;
import com.jetbrains.rest.RestUtil;
import com.jetbrains.rest.psi.RestReferenceTarget;
import org.jetbrains.annotations.NotNull;

import static com.intellij.patterns.PlatformPatterns.psiElement;
import static com.intellij.patterns.StandardPatterns.or;
import static com.jetbrains.rest.completion.ReferenceCompletionContributor.getPrefix;

/**
 * User : catherine
 */
public class DirectiveCompletionContributor extends CompletionContributor {
  public static final PsiElementPattern.Capture<PsiElement> DIRECTIVE_PATTERN = psiElement().afterSibling(or(psiElement().
    withElementType(RestTokenTypes.WHITESPACE).afterSibling(psiElement(RestReferenceTarget.class)),
       psiElement().withElementType(RestTokenTypes.EXPLISIT_MARKUP_START)));

  public DirectiveCompletionContributor() {
    extend(CompletionType.BASIC, DIRECTIVE_PATTERN,
       new CompletionProvider<CompletionParameters>() {
         @Override
         protected void addCompletions(@NotNull CompletionParameters parameters,
                                       @NotNull ProcessingContext context,
                                       @NotNull CompletionResultSet result) {
           int offset = parameters.getOffset();
           final String prefix = getPrefix(offset, parameters.getOriginalFile());
           if (prefix.length() > 0) {
             result = result.withPrefixMatcher(prefix);
           }
           for (String tag : RestUtil.getDirectives()) {
             result.addElement(LookupElementBuilder.create(tag));
           }
         }
     });
  }
}
